1. Field
Example embodiments herein relate to a carbon dioxide adsorbent including zeolite, a process for preparing the same, and a method of separating carbon dioxide using the same.
2. Description of the Related Art
A considerable increase in the concentration of global atmospheric CO2, one of the greenhouse gases, has raised concern about climate change and has led to increasing efforts in research and development on control of CO2 emissions. The main CO2 emission sources include fossil fuel-based power plants, vehicles, and manufacturing plants for cement, limestone, hydrogen, ammonia, and the like. Capture and separation of carbon dioxide from fixed facilities such as various power plants or factories are considered as first measures for the control of CO2 emissions. The capture of carbon dioxide refers to a process of physically or chemically separating CO2 among a gas mixture generated from chemical reactions or combustion of fossil fuels. In order to capture CO2 by adsorption, carbon materials, zeolites, metal-organic composite materials (MOF), or the like may be used. They show a certain level of adsorption efficiency at a low temperature of 0° C. to room temperature, but they have difficulties in being used for carbon dioxide adsorption in a higher temperature environment. Hydrotalcite shows adsorption capacity of about 1 to 2 wt % at a temperature of about 200 to 300° C. and under a normal pressure, but its adsorption capacity is too low to practically carry out a carbon dioxide adsorption process. Among fixed CO2-emission facilities emitting a considerable amount of carbon dioxide are fossil fuel-based power plants (e.g., an integrated gasification combined cycle (IGCC) system or a thermoelectric power plant) and natural gas wells. In order to address cost-related issues, power plants emitting a huge amount of carbon dioxide require adsorbent materials that may adsorb carbon dioxide at a relatively high temperature, for example, about 200 to 550° C.